Electric switch



Feb. 16 192e.- 1,573,179

J. N. MAHONEY ELECTRI C SWITCH Filed July 28. 1921 2 Sheets-Sheet 1 2Sheets-Sheet 2 J 4 f 4 4 4 a. WW/ "34m/ll mw m Feb. 16 1926.

J. N. MAHONEY ELECTRIC SWITCH Filed July 28 Patented Feb." l16, 1926.

-` UNITED STATES PATENT oEFlcE.

JOSEPH N. MAHONEY, OF BROOKLYN, NEW YORK, AAASSIGNOR, BY MESNE ASSIGTN-MENTS, TO CONDIT. ELECTRICAL MANUFACTURING CORPORATION, OF BOSTON,MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS. Y i

Y ELECTRIC SWITCH.v

Application led July 28, 1921. Serial No. 488,150.

To all 'whom z't may concern.'

yBe it known that I, J osEPH N. MAHONEY, a citizen of the United States,residing at Brooklyn. in the county. of Kings and State of New York.have invented an Improvement in Electric Switches, of which thefollowing lis a specification.

This invention relates to electric switches adapted to interrupt currentof considerable magnitude.

When a circuit is interrupted under load in oil a considerable amount ofenergy is liberated suddenly, which is made manifest irr severalA ways,one of which is the rapid and usually large increase in gaseous pressurewithin the switch. The sudden liberation of a large amount of energyresults in severe strains to the switch and, in the usual type ofswitch, may result in its rupture.

An object of this invention is to dissipate gradually energy liberatedupon circuit interruption as by utilizing saidI energy to set. in motionrelativelyv massive bodies, as bodies of oil in the switch, whereby theenergy will be absorbed, by said moving bodies, and circulate'the oiland subsequentlv bring the oil to rest gradually whereby to dissipatethe energy oi movement therein and at such a moderaterate that theenergy dissipation may be accomplished without undue strain on theswitch.

A- further object is to provide a switch having an outer spillreceptacle and an -inner oil-receptacle and both adapted to contain oilto substantially the same level; and means arranged to effect thecirculation of oil between there'ceptacles; and means arrangedautomatically to maintain the oil level in said inner receptacle.

A further objectis to effect the introduction of oil to the innerreceptacle by the movement of the inner oil receptacle due to circuitinterruption.

A further object of the invention is a ynovel method of supporting theinner oil receptacle yieldingly in position.

The switch embodying the invention may comprisea rigidly supported outeror spill receptacle and an inner oil receptacle movably disposed withinand spaced from the side wall of said spill receptacle and supportedyieldingly in position by a helicalspring disposed on the bottom of thespill receptacle and upon which said inner oil receptacle rests. Theinner oil receptacle may be formedlwith a neck which comprises a guideor positioning means for, and is disposed within said helical s ring;and an inwardly-opening Vcheck va ve may .be disposed in the neck andarranged normally to close the neck. Both receptacles are adapted to befilled with oil substantially to the same level.l Upon the interruptionof a suiciently heavy current, the inner oil receptacle will be moveddownwardlyngainst the spring 'by the resulting increase' of gaseouspressure within the switch, and due to the elevated level in the outerreceptacle, and also due to the downward movement of theinnerreceptacle, the valve will" open to establish communication between thetwo receptacles and oil will flow into the inner receptacle to restorethe oil level therein; and

oil may flow also over the top of and into said inner receptacle fromsaid spill receptacle.

A further object Yof the invention istgenerally to improve theconstruction and operation of an electric switch.

The broad idea of an inner and an outer receptacle with a valve in theinner receptacle to admit a flow of oil from the outer to the innerreceptacle is disclosed in a copending application of George A. Burnham,Serial No. 454,427, filed March 22, 1921; and the broad idea of an oilreceptacle supported upon a helical spring is disclosed in another'copending ap lication of George A. Burnham, Serial o. 463,773, filedApril 23, 1921, both applications being assigned to S. B. Condit. A

Fig. 1 is a longitudinal sectional elevation of an oil immersed electricswitch embodying the invention.

Fig. 2 is a detail similar to Fig. 1 but with the inner oil receptaclein a depressed position and the valve open to establish fluidcommunication between the inner and spill receptacles.

Fig. 3 is a detail of a modiied valve and illustrating-'the method ofopening it positively. y

Fig. 4 is a detail of theinner oil receptacle illustrating a modiiedform of neck.

, type of switch.

Fig. 5 is a detail of the switch frame removed from the oil receptaclesand looking upwardly into said frame.

Fig. 6 is a sectional detail along line 6 6 of Fig. 5.

i Fig.l 7 is a sectional elevation of a modlfied form of switchembodyingvthe invention.

Fig. 8 is a detail along line 8 8 of Fi Fig. 9 is a detail along line9-19 of Fig. 10 is a detail along line 10-10 of Fi 8. n

is here shown the invention is applled to the so-called removable-unittype of oil switch but is not limited to this speciiic The switchincludes the switch frame 10 comprising a cover for the spill and innerreceptacles hereinafter to be described; the stationary switch-members11 and movable switch member 12 supported by said frame; and the base13; and the rods 14 which connect said fra-me and base rigidly', and theframe 10 may be removed by first removing the nuts 14a of sald rods 14.A preferably cylindrical outer or spill re ceptacle, V15 having a moreor less semi- -spherical bottom 15n is supported on sald base 13; 'andsaid base is shaped to receive and form a cradle for said receptacle."Said spill receptacle is here shown as rigidly supported although 'itmay be supported otherwise. Said receptacle ektends upwardly above saidbase within sald rods and may be received within an outer peripheral lipl0* of lsaidframe; and said frame may be drawn down or seated againstthe top edge of said spill receptacle. A vent pipe 16 having the usualballies 16a therein, see Fig. 6, may be secured in lthe top of saidframe to establish communication between the expansion chamber A undersaid frame and above the surface of the oil in the spill receptacle andthe inner'receptacle hereinafter to be described. and the atmosphere.

A preferably cylindrical movable inner oil receptacle 18 having the moreor less semispherical bottom 18a is disposed within said spillreceptacle and is spaced from theside wall thereof by suitable means, asthe spacers 19, which may be secured to the inner face of the side wallof the spill receptacle and extended toward the inner receptacle toguide it for vertical movement.

Said frame 10 is formed with a plurality of internal lugs 20 spacedapart to provide Y a plurality of passages 21 therebetween; and saidinner receptacle is adapted to be held yieldingly in contact with saidlugs by resilient, means hereinafter to be described; and said passages21 will serve to establish equal gaseous pressures in said inner andspill receptacles and also serve to admit or facilitate the transfer ofoil from one to the other receptacle.

The bottom 18' of said inner receptacle 18 may be provided with a neck25, here shown as integrally formed with the bottom of the receptacle,although it may be otherwise formed, as-indicated at Fig. 4, forinstance, wherein the neck 25L is a separable member and is held inplace in an aperture in the bottom 18n of the receptacle by the {iange25" l.

and check nuti26. A oppet valve 27 1s disposed in said neck and isarranged to open mwardly, as shown, and normal y maintain closed the-uid passage throu h the neck and open toadmit ow of oi from said spillinto said inner oil receptacle when there is an elevated head of oil insaid s ill receptacle and pressure conditions wit in the switch are'favorable for such flow of oil.

A relatively stiff open helical spring 30 extends between the bottom 15of the spill receptacle and the bottom 18 of the inner receptacle andloosely encircles said neck and serves as a cradle to support said innerreceptacle yieldingly in place; and said neck may serve to maintain saidspring in position'.

Said spring is adapted preferably to press said inner oil receptacleyieldingly against the lugs 20 of the switch frame with considerableforce `whereby to load the receptacle and cause it to be unresponsive toa small and inconsequential pressure rise within the switch but torespond and move downwardly in response to a larger and possiblydangerous pressure rise.

Bothouter and inner receptacles are adapted to be filled with oil toapproximately the same level, as indicated in F ig. 1. When the switchis opened under load a relatively high gaseous pressure may be crcatedin the expansion chamber A of the switch and the inner receptacle 18will be forced downward against, and compress,

said spring 30, thereby to increase the volume of the expansion spaceand reduce the pressure rise and relieve the inner receptaclesupporting-Structure from shock.

Oil will be expelled upwardly from the inner receptacle by thecircuit-interrupting are into the switch frame and thereby absorb acertain amount of the energy liberated by the arc; and the oil willstrike against said frame and have its velocity reduced, thereby todissipate its energy of movement and thence will fall downward, aportion going back into the inner receptacle and the remainder passingthrough the passages 21 into the` spill receptacle; and the oil level inthe spill receptacle will be raised over that in the inner receptacle.The setting into motion of the inner receptacle will absorb asubstantial amount of energy and said receptacle will act asia pistpn topress against the body of oil in the spill receptacle and set the oiltherein in motion, resulting in a further absorption of energy. Thelevel of oil 1n the spill rece tacle may be such that oil may flow overt e top of and into the inner receptacle from the spill receptaclethereby restoring, at least partially, 011 expelled froml the innerreceptacle on circuit interruption. When the oil level in the spillreceptacle is sufficiently greater than the oil level inthe innerreceptacle, said valve 27 will be forced open and oil will flow from thespill receptacle through said neck into the bottom of the spill,receptacle, thereby to restore the oil level therein; and said valve maybe loaded or unloaded, by obvious means, not shown, to govern theoperation of the valve and the rateof flow of oil therethrough.,Inasmuel" as the gaseous ressure upon the oil in both receptacles 1s thesame, vby reason of the communicating passages 21, the transfer of oilthrough the neck may take place when there is a re1- ative difference4in oil level and regardless of the existence of an abnormal gaseouspressure Awithin the switch. Furthermore, the inner receptacle will actto some extent as a piston and operateA forcibly to open said valve 27by reason of the inertia of the lmass of oil in the spill receptacle andforce oil into the inner receptacle. `It will be noted that the switchis so arranged that substantial all of the oil is set in motion andmeans 1s provided for the circulation of oil from the outer to the innerreceptacle whereby to present fresh and cool oil to the action of thecircuit-interrupting arc. The skin friction ofthe wall fof the innerreceptacle in contact with the oil in the spill receptacle assist-s inabsorbing energy; and the t body of oil in the spill receptacle operatesas a hydraulic shock-absorber to absorb energy from the moving innerreceptacle and assist in gradually bringing it to rest and rendering itsreturn movement more gradual. It will be noted further that by varyingthe extent of opening of said valve and the area of the passage betweenthe spill receptacle into the inner receptacle, the-.movement of theinner receptae e may be governed by varying the resistance offered tothe circulation of oil through said valve and over the top of the innerreceptacle. A

In Fig. 3 the stem 27 of the valve 27 is somewhat longer than the sternvof the valve illustrated in Figs. 1 and 2 and said stem is adapted to bemoved against the bottom of the spill receptacle by the downwardmovement of the inner receptacle whereby to effect the positivel openingof the valve.

Said inner receptacle, preferably, is not attached to said helicalspring but merely rests removably upon it; and said receptacle,preferably, is not secured permanently in position but may be withdrawnupwardly from the spill receptacle.

Fig. 7 villustrates a. modified form of structure wherein the movementof thel inner oil receptacle el'ects the Imovement of the oil or otherenergy-absorbing fluid in the spill receptacle and in which fluidcommunication between the two receptacles is suppressed.

In Fig. 7 the yieldingly-'slupported inner oil receptacle 40 isimperf'orate at the bottom and the upper portion ot' its side wall ismovably received within the'annular wall 41 of the switch frame and maybe. a relatively tight sliding fit therein so that the friction betweenthe frame and receptacle may be substantial, whereby to absorb anddissipate energy of movement of the receptacle, although it will not beygreat enough tov restrain the receptacle from movement. A packing ring42 may be inserted in a groove in said wall 41 to engage the receptacleand prevent fluid communication between said outer and innerreceptacles. A separator ring 43 is disposed between the outer and innerreceptacles beneath the'oil level in the outer receptacle and isarranged to separate the oil spaces above and ,/b/elow it in the outerreceptacle; and said ring may be integral with the outer receptacle, ifdesired. A packing ring 44 may becarried 'by said ring and enga-ge theside wall of said inner receptacle to prevent fluid leakage along theside wall around said separator ring. although permitting movement ofthe inner receptacle. controlled by the downwardly-opening check-valves46, and a fluid passage 47 gov` erned by the adjustable valve stem 48may be formed through said vring to provide for fluid communication withthe fluid spaces above and below said ring. With the arrangement hereinillustrated there is no means for fluid communication between the outerand inner receptacles and, consequently, the outer leceptacle maycontain a fluid other than oil, as Water, for instance.

The form of struc-ture illustrated in Fig. 7 functions substantiallylike the structure illustrated in Fig. 1 with the distinction that thereis no transfer of fluid from the outer to the inner receptacle by reasonof the fluid tight seal between the inner recep-U tacle and switch frameand the absence of the valve. 'hen the inner receptacle is moveddownward upon its spring, due to pressure resulting from circuitinterruption, fluid is forced upwardly through the passages 47 in thering -43 into the space above said' ring and compresses the airor othergas above the fluid level therein and energy is thereby absorbed. Vhenthe pres- `sure within the inner receptacle due to circuit interruptionhas been relieved, or partially relieved, the innerl receptacle will bemoved upward by the action of its supporting spring and also by thepressure of the compressed gas in the outer receptacle, and

Fluid passages 45` fluidwill flow downward through the pas'- sages 45 insaid ring 43, whereby to restore the inner receptacle to its normalposition. It is apparent that the invention may beapplied to otherembodiments without departing from the spirit thereof.

I claim: 4 1. An electric switch having a fixed spill receptacle, amovable inner oil receptacle,

and means to support said inner receptacle 'yieldingly from the bottomof said spill receptacle.

2,. An electric switch having a fixed spill receptacle, resilient meansdisposed within `said receptacle at the bottom thereof, and

an inner oil receptacle supported movably upon. said resilient means.

3. An electric switch having a fixed spill receptacle, resilient meansdisposed within said receptacle at the bottom thereof, and an inner oilreceptacle supported removably upon said resilient means.

4. An electric switch having a fixed spill receptacle, a helical springdisposed within said receptacle ,upon the bottom thereof,

Vand an inner oil receptacle supported yieldingly upon said spring.

5. An electric switch having a spill receptacle, a helical springdisposed within said receptacle upon the bottom thereof, and

.an inner oil receptacle supported yieldingly upon said vspring having aneck disposed Within said spring.

6. An electric switch having a spill reccptacle, a helical springdisposed within said receptacle upon the bottom thereof, and

g A 9. An electric switch having a fixed spill receptacle, a movable oilreceptacle disposed within said spill receptacle having avalvecontrolled fiuid passage in its bottom, and means disposed aboutsiad passage arranged to support said inner receptacle yieldingly.

10. An electric switch having a spill re-A ceptacle, an oil receptacledisposed within said spill receptacle having its bottom formed with aneck, and a valve in said neck. i

11. An electric switch having a fixed spill receptacle, a movable oilreceptacle disposed within said spill receptacle having its bottomformed with a neck, and a valve in said neck.

, ceptacle.

12. An electric switch having a fixed spill receptacle, a movable oilrece tacle disposed within said spill receptacle aving' its bottomformed with a neck, a valve in said neck, and means to support saidinner receptacle yieldingly.

13. An electric switch having a fixed spill receptacle, a movable oilreceptacle disposed within said spill receptacle having its bottomformed with a neck, a 'valve in said neck, and means to support saidinner receptacle yieldingly comprising a helical spring disposed withinsaid spill receptacle upon the bottom thereof upon which said inner oilreceptacle is supported.

14.. An electric switch having a spill receptacle, a^ helical springdisposedwithin said receptacle ,upon the bottom thereof, a movable oilreceptacle disposed within said spill receptacle upon said spring, thebottom of'sai-:l inner oil receptacle having a neck disposed within saidhelical spring, and a valve in said neck.

15. An electric switch having a spill receptacle, a helical springdisposed within said receptacle'upon the bottom thereof, a

spill receptacle upon said spring, the bottom of' said inner-oilreceptacle having a neck disposed within said helical sprin and a valvein said neck arranged to open 1nto said inner oil receptacle.

16. An electric switch having a fixed spill receptacle adapted tocontain oil, a downwardly movable oil receptacle disposed within saidspill receptacle, switch members disposed within said inner oilreceptacle, said inner oil receptacle having a downwardlydirectedpassage through its bottom, and an inwardly-opening check valve arrangednormally toclose said passage. Y

17. An electric switch having a fixed spill receptacle adapted tocontain oil, a movable oil receptacle disposed within said spillreceptacle, and means governed by the movement of said inner oilreceptacle'to control the-admission of oil to said inner oil re- 18. Anelectric switch having a fixed spill receptacle adapted to contain oil,a movable oil receptacle disposed within said spill re! ceptacle, andmeans governed by the movement of said inner oil receptacle to controlthe admission of oil to said inner oil receptacle from said spillreceptacle.

19. An electric switch having a fixed spill receptacle adapted tocontain oil, a movable oil receptacle disposed-within said spill re-vceptacle having a fluid passage through its wall and a valve in saidpassage arranged positivelyto'be controlled by the movement `of saidinner oil receptacle.

' movable oil receptacle disposed within said y 20. An electric switchhaving a fixed spill receptacle and a movable inner receptacle bothadapted to contain oil to substantially the same level, means to supportsaid vinner rece tacle yieldingly in position and means to e ect thecircu ation of oil between said receptacles.` v Y 21. An electric switchhaving a fixed spill receptacle and a yieldingly-supported movable innerreceptacle both adapted to contain oil to substantially the same level,and means arranged to effect then transfer of oil from the spillreceptacle over the top of and into the inner receptacle.

22. An electric switch having a fixed vspill receptacle and ayieldingly-supported movable inner receptacle, both receptacles adaptedto contain oil, a switch frame comprismg a cover for both receptacleshaving a vent passage kthrough it and means to subject said receptaclesto the same gaseous pressure, said means including a passage arranged incommunication with both receptables and over the oil level therein.

23. An electric switch having a spill receptacle, a yieldingly-supportedmovable inner receptacle, both receptacles adapted to contain oil, aswitch-frame comprising a cover Vfor both receptacles, said innerreceptacle the movement of said receptacle comprising comprising apiston movable to force oil from said spill receptacle into said innerreceptacle.

24. An electric switch havinga spill receptacle, a ieldingly-supportedmovable innerl receptac e, both receptacles adapted vto contain oil, aswitch-frame comprising a cover for both receptacles, means to establishfluid communication between said receptacles, said inner receptaclecomprisin a yiston movable to e'ect the circulation o oi between saidtwo receptacles.

25. An electric switch having a movable oil receptacle, resilient meansarranged to support said receptacle yieldingly, and hydraulic means togovernA the movement of said receptacle. Y

26. An 'electric switch having a. movable oil receptacle and hydraulicmeans to govern 28. An electric switch including an oil' receptaclehaving its bottom formed with a neck, and a poppet valve disposed insaid neck normallyto close the upper end thereof and having a stemextended downwardly 'within and outwardly beyond said neck.

29. An electric switch having a receptacle adapted tc contain oil, amovable oil receptacle, and means governed by the movement of saidmovable oil receptacle to control the transfer cf oil between saidreceptacles.

30. An electric switchhaving a receptacle adapted to contain oil, amovable oil receptacle, and means governed by the movement of saidmovable oil receptacle to control the transfer of oil from said firstreceptacle to said movable receptacle.

.131. An electric switch having a movable oil receptacle, resilientmeans arranged to support said. receptacle yieldingly, and hydraulicmeans including said receptacle as an operative element arranged togovern the movement of said receptac e.

32. An electric switch including separable switch-members and twofluid-containing receptacles, .one of which surrounds saidswitch-members and is movable with respect to theV other receptacle andis constructed to move and'displace fluid in said other receptacle uponcircuit interruption.

In testimony whereof, I have signed my name to this specication.

JOSEPH N. MAHONEY.

